Mobile radio communication devices such as cell phone handsets have long employed chip-cards such as a Subscriber Identity Module (SIM) and, with regard to so-called 3G handsets, a Universal Integrated Circuit Card (UICC). Such cards are generally arranged to contain with caller and network related information and include memory and microcontroller functionality.
Such known chip-cards as are employed within mobile radio communication devices are becoming increasingly sophisticated and further functionality has included the provision of a server within the chip-card such that, for example, the UICC can operate in a server mode to one or more clients whether locally on the mobile radio communications device Mobile Equipment (ME), or remote therefrom.
While such chip-cards can readily be provided with such server functionality for communication with a client, scenarios also arise in which it is required that the server communicate with one or more of a plurality of clients each having the same IP address, such as for a plurality of local clients provided on the same ME as the chip-card server.
Communication between the chip-card server and the ME is generally supported by the Bearer Independent Protocol (BIP). However, the information payload delivered by way of the BIP channel does not include information serving to indicate the client from which the signaling originates and so there is no inherent way in which the server chip-card can distinguish between payloads originating from different clients each sharing the same IP address.
It is known to support Transmission Control Protocol (TCP) over a BIP channel, for example for a UICC in server mode, and wherein a plurality of clients sharing the same IP address are present. Here a single specific BIP channel is provided for each particular TCP connection. However, disadvantages arise insofar as the provision of a plurality of separate BIP channels is relatively resource-consuming for both the ME and, for example, the chip-card and additional provisions needs to be made so as to keep the data from different clients separate and which generally requires the provision of several buffers.
Additionally, overheads associated with the support of TCP over the BIP channel can prove disadvantageously limiting having regard to the relatively safe and secure environment in which the server chip-card ME interface operates.
The present invention seeks to provide for a method of communication in a mobile radio communications device between a chip-card in server mode and any one of a plurality of clients each having the same IP address, and which has advantages over known such methods. Likewise the invention seeks to provide for a related mobile radio communications device, and signal arising therein, and which exhibit advantages over such known devices and related signaling.